The present invention relates to a pneumatic tire having a tread portion with fine grooves for preventing bareness of rubber.
In the tires vulcanized in a mold, in particular those which have a block type tread pattern, the so-called bare, that is, bareness of the tread rubber tends to occur when the air between the tire and mold is not fully discharged. Therefore, to prevent the occurrence of bareness of the rubber, a mold with a large number of vent holes, and a vacuum mold or a segmental mold are usually used. If a large number of vent holes are utilized, a large number of spurs are inevitably formed in the tread portion of the tire. Thus the appearance is thus bad. It is necessary to cut out the spurs from the tread. However, to cut out the spurs without injuring the tread surface is a difficult or time-consuming undertaking. If the vacuum molds or segmental molds are used, the tire production cost becomes high due to high mold costs.